for new AIDS Vaccine
Efforts to develop an AIDS vaccine received a boost with research showing that an
experimental cold virus vaccine could control a virus similar to HIV in monkeys.
AIDS is a serious illness caused by infection with the human immunodeficiency virus (HIV).
HIV breaks down the body's immune system, so the person with AIDS can no longer fight off
disease successfully. As a result, secondary infections, cancers, and tumours occur more
easily. At this time, though there are anti-viral drugs for HIV there is no cure or
immunization that will prevent HIV infection, however a lot of research is being done for
The research was carried out by the Scientists at Merck. According to studies the cold
virus (adenovirus) vaccine did not prevent infection but significantly reduced HIV in
immunised animals and could provide important guidance about how to combat HIV/AIDS in
This cold virus vaccine is the most potent HIV vaccine that has been tested in monkeys to
date with a purely cellular immune response with corresponding control of infection. The
vaccine reduced the virus almost 1,000-fold in the vaccinated animals compared to monkeys
that had not been immunised. But in a separate study scientists at Harvard Medical School
in Boston showed that the HIV can mutate and outwit the initial immune system response
triggered by a similar vaccine strategy.
These two studies highlight the complexity of the search for an AIDS vaccine. In the
first, infection with a hybrid HIVSIV virus was effectively controlled in monkeys
immunized with genetic vaccines. The second study reports that mutations can allow HIV to
escape this immune control, emphasizing the challenges in developing an effective vaccine.
There are limitations of vaccines that control rather than prevent HIV infection, and the
difficulties faced by scientists trying to halt the worldwide epidemic that has infected
40 million people. However, the findings should not diminish the urgency or importance of
testing this vaccine in human candidates.
Nature January 2002, Vol. 415